I was looking at the I2C in RaspberryPi and I saw that they are pulled by 1.8K resistors(I am not talking about the ID pins). On the other hand, I got one of those RTC and they got two 222Ohm pull up resistor on board. My questions are:
First, why the would put a pull up resistor if the RaspberryPi got one?
Second, This resistors will divide the overall pull up resistors as they will be connected in parallel, this wouldn't effect I2C communication overall?